TCVN 9386:2012 - Earthquake Resistant Design

What this standard covers

TCVN 9386:2012 is the Vietnamese standard for the design of structures for earthquake resistance. It is closely based on Eurocode 8 and sets out how seismic action is determined and how structures are detailed to survive it.

The standard defines the seismic action through a design response spectrum built from the site ground acceleration, the ground type, and a behaviour factor reflecting how much ductility the structural system can deliver. A more ductile system attracts a lower design force but must be detailed to justify it.

It sets out the analysis methods permitted - from the lateral force method for regular buildings to modal response spectrum analysis where regularity conditions are not met - and the detailing rules for ductility class, which govern confinement reinforcement, capacity design of columns relative to beams, and the joint detailing that lets a frame form plastic hinges without failing in shear.

What you will find in it

Seismic zoning

The ground acceleration to be taken for a site in Vietnam, which is what sets the scale of the seismic action for the whole design.

Ground types

Classification of the soil profile beneath the structure, and the amplification it applies to the ground motion - soft sites attract markedly more action than rock.

Response spectrum

The design spectrum used to derive the seismic force from the period of the structure, which is the normal route into an analysis.

Behaviour factor

The reduction applied to the elastic force to account for ductility, and the structural systems and detailing standards that justify each value.

Regularity

Criteria for regularity in plan and elevation, since irregularity restricts which methods of analysis may be used and reduces the behaviour factor.

Capacity design and detailing

The rules that force yielding into chosen ductile zones and keep brittle failure modes - shear, connections, joints - stronger than the members that frame into them.

When to use this standard

Open TCVN 9386 when a structure in Vietnam must be checked for earthquake. It gives the seismic action and the design and detailing rules that go with it; the gravity design still follows TCVN 5574 or TCVN 5575, and the seismic action is combined with the other actions using TCVN 2737.

How it fits with the other standards

Seismic action from this standard is combined with the gravity and wind loads of TCVN 2737, and the resulting forces are checked against member capacities to TCVN 5574 for concrete or TCVN 5575 for steel.

What each part and section covers

Phần 1

The building part, pp. 11-254 - by far the larger half. Adopts EN 1998-1 with Vietnamese-specific zoning and importance factors substituted in.

P1 - Mục 1

Scope, normative references, assumptions, the distinction between Principles and Application Rules, terms and definitions, symbols and SI units.

P1 - Mục 2

Performance requirements - no-collapse and damage-limitation - and the compliance criteria that verify them.

P1 - Mục 3

Ground conditions and the seismic action: site classification (3.1), then the design response spectra and the alternative representations of the action (3.2).

P1 - Mục 4

Design of buildings. Characteristics of earthquake-resistant buildings including regularity (4.2), structural analysis methods (4.3) and the safety verifications (4.4).

P1 - Mục 5

Concrete-specific rules: design concept, design to EN 1992-1-1, the medium (DCM) and high (DCH) ductility classes, anchorage and splices, foundation members, infill effects and precast structures.

P1 - Mục 6

Steel-specific rules: structural types and behaviour factors, dissipative detailing, moment frames, concentrically and eccentrically braced frames, inverted-pendulum structures, and design and construction control.

P1 - Mục 7

Composite steel-concrete rules: materials, structural types and behaviour factors, member rules, composite moment frames, braced frames and composite shear walls.

P1 - Mục 8

Timber-specific rules: materials and dissipative zones, ductility classes and behaviour factors, analysis, detailing and safety verification.

P1 - Mục 9

Masonry-specific rules: materials and bond, building types and behaviour factors, analysis, design and construction criteria, and the provisions for simple masonry buildings.

P1 - Mục 10

Base isolation: definitions, basic requirements, the seismic action and behaviour factor for isolated structures, properties of the isolating system, analysis, and ultimate-state safety verification.

Phần 2

The geotechnical part, pp. 255-288, adopting EN 1998-5 - what the ground and the foundation must satisfy under seismic action.

P2 - Mục 2

Definition of the seismic action for geotechnical purposes and its time-history representation.

P2 - Mục 3

Soil properties: strength parameters, and the stiffness and damping parameters used in a seismic ground response.

P2 - Mục 4

Site selection and ground investigation, including proximity to faults, slope stability and liquefaction-susceptible ground.

P2 - Mục 5

Foundation systems: general requirements, rules for the design action effects, and the verification and sizing criteria.

P2 - Mục 6

Soil-structure interaction: when dynamic interaction effects must be taken into account, including for piles.

P2 - Mục 7

Retaining structures: general requirements, selection and design considerations, methods of analysis, and verification of strength and stability.

Related standards

Tools that implement this standard